Hypomyopathic dermatomyositis associated with interstitial lung disease and good response to mycophenolate mofetil: case-based review

Abstract

Hypomyopathic dermatomyositis (HDM) is a rare form of dermatomyositis (DM). Interstitial lung disease (ILD) associated with clinically amyopathic DM (CADM-ILD) or hypomyopathic DM (HDM-ILD) is a rare condition with a more unfavorable prognosis than ILD associated with classic DM (CDM-ILD). There is no effective treatment for HDM-ILD. A 62-year-old woman with a 6-month history of chronic polyarthritis and myalgia presented skin lesions characteristic of DM (erythematous lesion on extensor surface of elbows, Gottron's papules, V-neck sign) with no clinical muscle impairment (global muscle strength: grade 5). Muscle enzymes (creatine kinase, lactic dehydrogenase, and aldolase) and electroneuromyography (ENMG) were normal. Computed tomography of the chest revealed ILD. Magnetic resonance imaging and muscle biopsy revealed subclinical muscle impairment. High doses of corticosteroids were used without success. As an alternative, 1500 mg/day of mycophenolate mofetil (MMF) was combined with low doses of prednisone, and the patient demonstrated a good clinical response after 3 months of this combination. Twenty-five months after initiating treatment, ILD remains in remission with the use of MMF and a low dose of prednisone. Therefore, MMF can be a good option for the treatment of HDM-ILD.

Advances in Juvenile Dermatomyositis: Myositis Specific Antibodies Aid in Understanding Disease Heterogeneity

“…MMF given to 50 children with JDM was both corticosteroid sparing and decreased muscle and skin inflammation without leukopenia or an increased number of infections (103). Adult DM with ILD responded well to MMF (104). Associated with congenital malformations, MMF should be discontinued 7 weeks before a planned pregnancy.…”

Aggressive multi‐combination therapy for anti‐MDA5 antibody‐positive dermatomyositis‐rapidly progressive interstitial lung disease

“…While there was no significant difference in infection rates between the two groups, the incidence of leukopenia was higher in the new treatment group. 17 An improvement in %FVC and a reduction in steroid dosage have also been reported in 32 PM/DM-ILD cases using MMF. 18 One case of an anti-MDA5 antibody-positive DM-ILD patient treated with PSL, MMF, and IVIg has been reported, with improvement in cutaneous and muscular symptoms and without worsening of ILD.…”

“…Koyama et al. reported that clinical symptoms, respiratory function, and radiographic findings improved in eight of 10 patients with CADM‐ILD treated with MMF 17 . An improvement in %FVC and a reduction in steroid dosage have also been reported in 32 PM/DM‐ILD cases using MMF 18 .…”

Potential of Krebs von den Lungen‐6 as a predictor of relapse in interstitial pneumonia with anti‐aminoacyl tRNA synthetase antibodies‐positive dermatomyositis

“…In ARS‐DMIP patients with high relapse risk, slow reduction of GC and CNI dosage is recommended to suppress IP activity in the long‐term. When the reduction of CNI dosage is inevitable because of adverse events, additional combination treatment should be considered using intravenous cyclophosphamide therapy, azathioprine and mycophenolate mofetil which have been reported to be effective for DMIP …”